Did you pull that PCB from an old boombox or did you etch it yourself? I would really like this to monitor not only HD/CD activity, but possibly my NIC activity as well. Please make a real instructable.
Congratulations! Your idea looks nice, but in this form it is not an instructable. People visiting "Instructables" web pages are interested in "how to make it". Please add pictures and instructions.
http://www.instructables.com/id/Hard-Disk-Drive-Activity-metre/